Opening-wedge high tibial osteotomy: a seven - to twelve-year study

Background: Medial opening wedge high tibial osteotomy (HTO) for the treatment of varus gonarthrosis can be associated with inadvertent decreases in patellar height. Hypothesis: Decreases in patellar height observed after medial opening wedge HTO can be minimized with the addition of a tibial tubercle osteotomy (TTO). Study Design: Cohort study; Level of evidence, 3. Methods: Twenty-nine patients undergoing medial opening wedge HTO with a concurrent TTO were matched with 29 controls who previously underwent medial opening wedge HTO without a TTO. Both groups had substantial varus malalignment (mean mechanical axis angle, −10° ± 3°) requiring large corrections. Measurements of patellar height and posterior tibial slope were calculated from standing lateral radiographs and compared preoperatively and 6 months postoperatively. Patellar height measures included the Blackburne-Peel index, Caton-Deschamps index, Miura-Kawamura index, Insall-Salvati ratio, and modified Insall-Salvati ratio. Results: The changes in the Blackburne-Peel, Caton-Deschamps, and Miura-Kawamura indices were significantly less in the HTO/TTO group versus the HTO group. There were 3 of 29 (10%) new cases that met the radiographic criteria for patella infera in the HTO/TTO group versus 11 of 29 (38%) new cases of patella infera found postoperatively in the HTO group, suggesting an absolute risk reduction of 28% with TTO. The changes in the Blackburne-Peel and Caton-Deschamps indices were correlated to a larger preoperative varus deformity in the coronal plane (r = 0.52 and r = 0.41, respectively). Conclusion: The addition of a TTO when performing a medial opening wedge HTO minimizes the decreases in patellar height associated with the procedure.

BackgroundAn iatrogenic lateral hinge fracture is a common intraoperative problem that may occur during medial open wedge high tibial osteotomy (MOWHTO). This study aims to assess the significance of using additional crossing lateral K-wires and their advantage in protecting the lateral hinge during MOWHTO procedures.MethodsThe data of patients fulfilling the inclusion criteria who underwent MOWHTO between May 2021 and August 2022 were retrospectively evaluated. One group had additional lateral hinge crossing K-wires (+ MOWHTO group), while the other did not (-MOWHTO group). Both groups were assessed for rate of intraoperative lateral hinge fractures, knee injury and osteoarthritis outcome score − 12 (KOOS-12), medial proximal tibial angle (MPTA), time of union, and time to return to work. The outcomes were compared using the independent T-test for continuous variables and the Fisher Exact test for nominal variables. A p-value of < 0.05 was considered statistically significant for both tests.ResultsThe study included forty-eight patients; twenty-four in each treatment group. The mean follow-up durations were 30.5 ± 3.6 months for + MOWHTO and 31.6 ± 3.2 months for –MOWHTO (p = 0.26). There was no statistically significant difference regarding mean age, sex, KOOS-12, MPTA, and time of surgery between both groups. The + MOWHTO group had a faster time of union (p = 0.001), an earlier return to work (p = 0.002), and a lower rate of intraoperative lateral hinge fractures (p = 0.04).ConclusionThis study demonstrated that using additional crossing lateral K-wires during MOWHTO had a beneficial effect on reducing the rate of iatrogenic lateral hinge fractures, with a faster time of union, and an early return to work. The KOOS-12, MPTA, and mean operative time did not reveal significant differences between treatment groups.Level of evidenceretrospective cohort comparative study; level III.

Patellar height changes sequentially after medial open wedge high tibial osteotomy: Evaluation using shear wave elastography

ABSTRACTPurposeKnee osteoarthritis (OA) is the most common degenerative joint disease in the world. It results in not only physical limitation and pain, but also negatively impacts quality of life and mental wellbeing. Treatment options such as medial opening wedge high tibial osteotomy (MOWHTO) help to relieve pain and improve functionality, but there is limited literature on the effect on mental health. This study aims to investigate the effect of MOWHTO on the mental health of patients with knee OA.MethodsIn this retrospective cohort study, data were collected from patients who underwent MOWHTO between 2019 and 2023 in a single tertiary institution. The main outcome score, short form‐36 mental component score (SF‐36 MCS), was recorded at baseline, 6 months and 2 years postprocedure. Secondary outcomes included the SF‐36 physical component score (PCS) and Oxford knee score (OKS).ResultsThere were a total of 108 MOWHTOs, comprising 51 men and 57 women. At surgery, the mean age was 55.4 ± 6.97. Twelve patients did not turn up at the 6‐month follow‐up. There was a significant improvement of SF‐36 MCS from a preoperative mean of 50.8 ± 12.6 to 57.1 ± 11.0 (p < 0.05) and 56.8 + 9.07 (p < 0.05) at 6 months and 2 years postoperation, respectively. There was also a significant increase in the scores of SF‐36 PCS and OKS (p < 0.05 for both) at 6‐month and 2‐year follow‐up. Higher preoperative SF‐36 MCS was significantly correlated with improved postoperation SF‐36 PCS (ρ = 0.184, p = 0.05) and OKS (ρ = −0.218, p = 0.02 < 0.05).ConclusionsAt 2‐year follow‐up, MOWHTO results in a significant improvement in the mental health of patients with knee OA. There is a correlation between preoperative mental health and postoperative outcomes, suggesting a role of mental health in affecting MOWHTO outcomes.Level of EvidenceLevel IV.

PurposeAn observation was made by the senior author of this paper that patients reported changes in their hip function after a medial opening wedge high tibial osteotomy (MOHTO) for varus pattern osteoarthritis. Alignment changes at the hip after MOHTO have not been previously documented. This study assesses coronal alignment changes at the hip after MOHTO.MethodsWe retrospectively analysed pre- and post-operative lower limb alignment radiographs of patients who underwent MOHTO. The medial proximal tibial angle (MPTA) and mechanical axis deviation (MAD) were measured to assess the alignment changes created by the MOHTO. The coronal alignment changes at the hip were evaluated using the mechanical greater trochanter angle (MGTA).Results29 osteotomies in 27 patients were included in this study. Results showed MOHTO created alignment changes at the hip. A positive correlation was found between the size of the correction at the knee and the subsequent changes at the hip. The change in the MGTA had a stronger correlation with the MAD than with the change in MPTA (r = 0.684 vs. 0.585). It was found that age, weight, height and BMI had no significant influence on these correlations.ConclusionsIncreased correction by the MOHTO lead to increased change in the coronal alignment of the hip. These changes are likely to result in an alteration in the weight bearing portion of the femoral head and the function of the abductors and we recommend assessing the hip joint as part of pre-operative planning.Level of evidencePrognostic level IV.

MRI findings change after medial opening-wedge high tibial osteotomy for medial knee osteoarthritis

Medial opening wedge high tibial osteotomy (MOWHTO) is an effective surgical procedure for joint preservation in active patients with medial knee osteoarthritis (KOA). However, older patients and those with prolonged preoperative sports cessation often struggle to resume high-impact activities, such as running, after MOWHTO. Remote rehabilitation tools may help overcome these challenges. We report the case of an older woman with prolonged cessation of sports activity who resumed sports activity after MOWHTO with the help of the mymobility® smartphone application. A 71-year-old woman with Kellgren-Lawrence grade 3 medial KOA and -5° varus alignment underwent MOWHTO. She discontinued daily 7 km runs for two years owing to knee pain. The preoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) scores were 53 for Symptoms, 50 for Pain, 61 for Activities of Daily Living, 25 for Sport and Recreation Function, and 6.25 for Quality of Life, and the Oxford Knee Score (OKS) was 31. Bone union was achieved on postoperative day (POD) 90. However, she maintained a low step count (approximately 2000 steps/day) and was unable to run owing to anxiety. We used mymobility® to provide chat-based guidance, step-count goals, and video assessments of jogging and running form. Activity progressively increased, and she achieved jogging ability on POD 150 and pain-free running ability on POD 180. Her Visual Analog Scale score improved to 0 mm, KOOS and OKS scores improved substantially, and step count increased to approximately 8000 steps/day. This case indicates that mymobility® can facilitate safe and timely return to sports after MOWHTO by improving motivation, providing remote supervision, and enabling individualized activity progression. mymobility® may be particularly effective for older patients or those who cannot access specialized postoperative rehabilitation services.

Bioabsorbable Magnesium-Based Bulk Metallic Glass Composite (BMGC) for Improved Medial Opening Wedge High Tibial Osteotomy in Knee Osteoarthritis

Background:Whether lateral hinge fracture (LHF) after open-wedge high tibial osteotomy (OWHTO) is associated with the change in tibial posterior slope (PS) has not been determined. Risk factors for PS increase are still unknown.Hypothesis:There will be no difference in patient characteristics and radiographic factors when stratified by change in tibial PS (ΔPS).Study Design:Cohort study; Level of evidence, 3.Methods:We reviewed the records of 148 patients who underwent OWHTO with locking-plate fixation from 2010 to 2016. Included were those with a minimum 2-year follow-up and true lateral radiographs before and at 1 year after surgery. ΔPS was defined as a difference between preoperative and 1-year postoperative PS, with positive values indicating PS increase. ΔPS was classified into <3°, 3° to <6°, and ≥6°. Any LHFs were grouped by Takeuchi classification as stable (type 1) or unstable (types 2 and 3). Risk factors for PS increase were evaluated using ordinal logistic regression analyses. Clinical outcomes according to ΔPS were evaluated using the Hospital for Special Surgery score.Results:There were 79 (53.4%) patients with ΔPS <3°, 44 (29.7%) with 3° ≤ ΔPS < 6°, and 25 (16.9%) with ΔPS ≥6°. LHFs were observed in 41 (27.7%) patients: 32 with type 1 and 7 and 2 with types 2 and 3, respectively. Results of the multivariate ordinal logistic regression analysis indicated that ΔPS was associated with unstable LHF (P = .005, exp[β] = 6.34), preoperative PS (P = .028, exp[β] = 0.90), and correction angle (P = .037, exp[β] = 1.09). ΔPS ≥6° was seen in 4 of 9 (44.4%) patients with unstable LHF, 9 of 32 (28.1%) with stable LHF, and 12 of 107 (11.2%) with no LHF (P = .017). The mean correction angle was 11.3° ± 3.6° in patients with ΔPS ≥6°, 9.4° ± 4.6° in cases of 3° ≤ ΔPS < 6°, and 8.8° ± 3.6° in cases of ΔPS <3° (P = .019). Hospital for Special Surgery scores did not differ according to ΔPS.Conclusion:LHF type and correction angle were associated with ΔPS after OWHTO, and unstable LHF and large correction angle were risk factors for PS increase. There was no significant difference in clinical outcomes according to ΔPS.

To compare clinical and radiological outcomes of medial opening wedge high tibial osteotomy (MOWHTO) using two different alignment methods: the alignment rod (AR) versus the gap measurement (GM) method. The primary outcome was to report the surgical accuracy of coronal plane corrections in each method. Patients who underwent MOWHTO with either AR or GM method between 2014 and 2022 at a single institution, with a minimum of 2 years of follow-up, were included. The opening gap was gradually spread with an AR under fluoroscopic control in the AR group, whereas the osteotomy site was opened to the value of the measured gap distance in addition to the thickness of the bone saw in the GM group. Radiological assessment of geometric characteristics included hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle and joint line convergence angle. Surgical accuracy, which is the deviation (Δ) between the intended and achieved correction, was compared between both methods. Clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Scores. A total of 110 patients (n = 110 knees) with a mean age of 54.1 ± 8.4 years were included in the study. Radiological parameters were significantly improved as reflected by HKA correction from 171.6° ± 2.0° to 181.1° ± 2.6° in the AR group and from 171.0° ± 2.3° to 181.1° ± 2.8° in the GM group at 2 years (Intergroup n.s). There was no significant intergroup difference for all radiological parameters and clinical outcomes. There was no intergroup difference in the surgical accuracy as evaluated by Δvalues and absolute Δvalues of both HKA and MPTA (n.s). Comparable correction accuracy was achieved in MOWHTO using either the AR or GM method. The GM method is simple and reliable in achieving the intended correction in MOWHTO. Ⅲ retrospective comparative study.

Patient-Specific Instrumentation in Medial Proximal Tibial Angle-Based Medial Open Wedge High Tibial Osteotomy: Improved Correction, Accuracy, and Cartilage Regeneration at Second-Look Arthroscopy.

Objective The purpose of this study was to evaluate the usefulness of preoperative planning of the femurofibular angle (FFA) in medial open-wedge high tibial osteotomy (OWHTO) for mild medial knee osteoarthritis. Methods Thirty-two patients (32 knees) with mild medial knee OA were retrospectively reviewed. The patients underwent preoperative planning of the FFA for OWHTO. For preoperative planning, a full-length weight-bearing X-ray photograph of the lower limb was opened within Adobe Photoshop Software, and a targeted corrective mechanical axis line of the lower limb and its intersecting point at the lateral tibial plateau surface was drawn using rectangle selection and filling tools. A frame, which encircled the tibia and fibula, was created around the predicted osteotomy plane and then rotated until the ankle center was on the targeted mechanical axis line. Subsequently, a distal femoral condyle line and a proximal fibula axis line were drawn, and the angle between the two lines was measured and defined as the femurofibular angle (FFA). During biplane OWHTO, the preoperatively determined FFA was used to complete the correction of the mechanical axis. During follow-up, the postoperative mechanical weight-bearing line (WBL) of the lower limb, the mechanical femorotibial angle (mFTA), and the FFA were measured and compared with the preoperatively determined values. Results The mechanical WBL shifted from a preoperative value of 25.36 ± 5.02% to a postoperative value of 56.19 ± 0.10% from the medial border along the mediolateral width of the tibial plateau, and it was 56.57 ± 0.08% at the final follow-up (P < 0.01). The preoperatively determined value was 56.25%, and no significant difference was found compared with postoperative week-one and final follow-up values (P > 0.05). The mFTA was corrected from a preoperative varus of 4.02 ± 0.63° to a postoperative week-one valgus of 2.37 ± 0.28°, and it had a valgus of 2.48 ± 0.39° at the final follow-up (P < 0.01). No significant difference in the valgus was found compared with the postoperative week-one, final follow-up and preoperatively determined valgus of 2.34 ± 0.26° (P > 0.05). The postoperative week-one and final follow-up FFAs were 90.34 ± 1.53° and 90.33 ± 1.52°, respectively, and no significant difference was found compared with the preoperatively determined value of 90.12 ± 1.72° and the intraoperative setting value of 90.25 ± 1.67° (P > 0.05). All corrected values were within the acceptable range of preoperative planning. Conclusion Preoperative planning of the FFA may be useful in OWHTO for patients with mild medial knee OA. Satisfactory correction of the postoperative targeted mechanical axis line of the lower limb can be obtained.

Background: Genu varum is a common deformity that leads to increased medial compartment loading and progressive osteoarthritis of the knee. High tibial osteotomy (HTO) is a well-established joint-preserving procedure that corrects malalignment and redistributes load. Among its variations, the uniplanar medial open-wedge method offers accurate correction with minimal complications. Aim: This research aimed to assess the short-term functional and radiological results of uniplanar medial open-wedge high tibial osteotomy in adult patients with genu varum. Methods: Prospective research has been performed on twenty adult cases had symptomatic genu varum who underwent uniplanar medial open-wedge HTO utilizing a T-buttress plate and autologous iliac crest bone graft. Patients were followed for at least twelve months. Clinical results have been evaluated utilizing the Visual Analogue Scale (VAS) and Lysholm Knee Scoring Scale (LKSS), while radiological parameters included varus angle, medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle (mLDFA), tibial slope and patellar height (Insall–Salvati index). Results: The mean age of patients was 34.65 ± 9.92 years, with 11 males (55%) and 9 females (45%). Postoperatively, VAS significantly enhanced from 8.15 ± 0.67 to 3.45 ± 0.94 (p = 0.001), and LKSS increased from 53.65 ± 8.85 to 86.6 ± 7.08 (p = 0.001). Based on LKSS grading, 5 patients (25%) achieved excellent, 13 (65%) good, and 2 (10%) fair to poor outcomes. Radiologically, varus angle improved from 12.83 ± 3.96° to 0.76 ± 3.45° (p < 0.001) and MPTA from 80.31 ± 2.74° to 89.72 ± 2.04° (p < 0.001). The tibial slope and patellar height showed slight, non-significant changes. Complications occurred in 3 patients (15%): Infection (5%), delayed union (5%) and lateral hinge fracture (5%), all managed conservatively with complete recovery. Conclusion: Uniplanar medial open-wedge high tibial osteotomy resulted in significant functional improvement, pain relief and precise alignment correction in patients with genu varum with minimal complications. It remains an effective joint-preserving option for young and middle-aged adults with medial compartment overload.

PurposeMedial knee osteoarthritis can be treated with medial open wedge high tibial osteotomy (OWHTO). We sought to investigate osseous consolidation of the osteotomy with and without autologous bone grafts (ABG) to detect possible benefits of ABG in osseous healing and functional outcome.MethodsIn this prospective study, patients without graft transplantation were compared to those receiving ABG after medial OWHTO. They were followed up 6 weeks, 12 weeks, 6 months and 12 months postoperatively. Radiographic progress of consolidation, clinical scores, contrast-enhanced ultrasound (CEUS) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) were assessed at each appointment.ResultsA total of 35 patients were enrolled, 20 without and 15 with graft transplantation. Radiologic evaluation showed a significantly earlier consolidation of the osteotomy gaps (p = 0.012) in patients with ABG, resulting in a significantly higher rate of consolidation 12 months after surgery (60% without bone graft vs. 100% with bone graft, p = 0.006). At 6 weeks as well as 6-month follow-up, a tendency of earlier consolidation with ABG was apparent, but not statistically significant (6 weeks: 50% vs. 80%, p = 0.089; 6 months: 30% vs. 60%, p = 0.097). CEUS and DCE-MRI showed physiological perfusion of the osteotomy gaps in both groups. A tendency to better function and less pain in patients with ABG was recognizable.ConclusionIn our study, autologous bone grafting evocated earlier osseous consolidation after medial OWHTO and showed a tendency to a better functional outcome.

Background: Medial open-wedge high tibial osteotomy (OWHTO) requires the release of the superficial medial collateral ligament (sMCL). However, research on medial laxity among patients who undergo OWHTO is rare. Purpose: To evaluate the changes in medial laxity of the knee joint as related to the complete release of the sMCL through serial valgus stress radiographs in patients who underwent OWHTO. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 48 patients (54 knees) who received OWHTO and were followed for more than a year and for whom serial valgus stress radiography data were available were retrospectively reviewed. To assess the medial laxity of knee joint, medial joint space opening (MJO) was measured while valgus stress of 15 kgf was loaded on the knee joint. The MJO was measured before surgery, during surgery before release of the sMCL under anesthesia, after the release, and after fixing with a TomoFix plate following the opening of the osteotomy site, as well as 3, 6, and 12 months after surgery. Serially measured MJOs were analyzed to evaluate the changes of medial laxity. Results: The MJO significantly increased after the release of the sMCL (mean ± SD, 12.2 ± 1.2 mm) compared with before the release (9.0 ± 1.1 mm) (P < .001). The MJO measured after fixing with the TomoFix plate following the opening of the osteotomy site (9.2 ± 1.2 mm) was significantly decreased compared with that measured after the release of the sMCL and was not significantly different from the MJO measured before release of the sMCL. No significant difference was observed among MJOs that were measured 3, 6, and 12 months after surgery. Comparison of MJOs before and after surgery also showed no significant differences. Conclusion: Complete release of the sMCL during OWHTO increases the MJO. However, the MJO decreased to the level before sMCL release after fixing with the TomoFix plate following the opening of the osteotomy site. Medial laxity induced by the complete release of the sMCL can be recovered by opening the osteotomy site.